There is a considerable need for small conferences on secialized topics in immunology to complement the major national scientific meetings. The Gordon Conferences provide an opportunity for specialists in a given area of research to convene in an informal and isolated setting, to present papers and exchange ideas over a period of several days. The Gordon Conferences cover a wide range of disciplines and cannot deal with the variety of specialized topics of interest to members of FASEB. The new series of conferences is designed to fill this need. The modest fee for registration and room and board (about $250) should facilitate attendance by students and young investigators. In this application we are requesting support for a conference on "Mononuclear Cell and Antibody Networks". The topic is timely and should be of interest to a large number of immunologists. There have been many recent developments in this field, including demonstrations of sets of T cells of different subtypes that interact with one another or with macrophages to generate either help or suppression, and the growing evidence for the importance of idiotype networks, at least at the level of the T cell. The existence of several soluble factors that can substitute for T cells or macrophages is now well established, but their precise biological functions remain to be elucidated. The question of immune regulation is of profound importance from the standpoint of any disease process in which a beneficial, or harmful, immune response can play a role.